CN113215658A

CN113215658A - Centimeter-level length perovskite single crystal fiber and preparation method and application thereof

Info

Publication number: CN113215658A
Application number: CN202110395718.5A
Authority: CN
Inventors: 陈东丹; 陈紫烨; 虞华康; 杨中民; 张勤远; 徐涛
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-08-06
Anticipated expiration: 2041-04-13
Also published as: CN113215658B

Abstract

The invention belongs to the field of single crystal growth, and discloses a centimeter-level length perovskite single crystal fiber and a preparation method and application thereof. The preparation method comprises the following steps: absorbing the perovskite precursor solution into a hollow fiber pore channel by capillary force or injecting an external force into the hollow fiber pore channel; the fiber tunnels were dried in a vacuum oven. The preparation process is simple, the high-quality bromine-based perovskite single crystal (i.e. the single crystal which is colorless and transparent, has good integrity and is not easy to crack) without macroscopic and microscopic defects can be obtained by sucking the liquid perovskite precursor gain medium by virtue of capillary force or injecting the liquid perovskite precursor gain medium by virtue of external force, the single crystal is tightly attached to the quartz template, the quartz template isolates air and moisture in an external environment, and the storage performance of the crystal is improved. The obtained perovskite single crystal in the tube emits strong green light under the excitation of laser, shows obvious ASE characteristics and has the potential of realizing laser emission.

Description

Centimeter-level length perovskite single crystal fiber and preparation method and application thereof

Technical Field

The invention belongs to the field of growth of single crystal fibers, and particularly relates to a centimeter-level length perovskite single crystal fiber and a preparation method and application thereof.

Background

The metal halide perovskite is used as an optical gain medium, and has wide tunable band gap (1.43-2.3 ev), high absorption coefficient, high photoluminescence quantum yield and high carrier mobility, so that the metal halide perovskite has great diversity in the fields of photovoltaics, photoelectric detection, optical pumping laser, radiation detection and the like. For example in the photovoltaic field, metal halide perovskites (CH)₃NH₃PbI₃) Was first applied in 2009 as an absorber for solar cells in the field of solar cells, so that the solar cells obtained a photoelectric conversion efficiency of 3.8% (Kojima a., Teshima k., Shirai y., et al]J.Am.chem.Soc.,2009,131(17): 6050-. 2018 polycrystalline CsPbI with super large grains₃The film perovskite realizes 15.71 percent PCE (power conversion efficiency), and in 2019, the high-crystalline beta-phase CsPbI₃The film achieved a PCE of 18.4%. Heretofore, polycrystalline perovskites have been associated with a decrease in ion and carrier mobility and the like due to grain boundaries, voids and defects present therein, and compared with them, single crystal perovskites have a wider absorption spectrum, high carrier mobility, long carrier lifetime and higher stability. Single crystals are more reflective of the intrinsic physical properties of semiconductors and generally exhibit better electronic properties than nano-or polycrystalline forms of the same compound. With MAPbI₃For example, the carrier mobility of a single crystal can reach 200cm² V^-1s^-1(the carrier mobility of the thin film is 0.4-40 cm² V^-1s^-1) The lifetime can reach 500 mu s (film andthe carrier mobility of the nanocrystal is 4.5-1000 ns).

Although there are many crystallization methods of perovskite crystals, for example, a chemical vapor deposition method, a thermal injection method, a cooling recrystallization method, an inversion temperature crystallization method, a vapor diffusion-assisted crystallization method, and the like. It remains a challenge to obtain the desired particle orientation, shape and size due to the non-directionality of the crystallization. At the same time, although the conversion in situ (Yang S., Zheng Y.C., Hou Y., et al.Formation mechanism of freestanding CH)₃NH3PbI3 functional crystals:in situ transformation vs dissolution crystallization[J]Chem. mater, 2014,26(23): 6705-6710) and dissolution recrystallization mechanisms (Fu Y, Meng F, Rowley M.B., et al. solution growth of single crystal methyl cellulose ester nanostructures [ J. for optoelectronic and photonic applications]J.Am.chem.Soc.,2015,137(17): 5810-5818) have been reported as the classical formation mechanism of independent perovskite crystals, but the understanding of the synthesis mechanism and crystal surface stability of independent single crystals is not clear. Therefore, it is of great significance to research a new method for preparing high-quality perovskite single crystals and further explore the growth and laser emission characteristics of the perovskite single crystals. Synthesis of colloidal MAPbBr by solution method from P é rez-Prieto and colleagues in 2014 for the first time₃Since the nano-crystalline, some discrete perovskite micro-and nano-structures, such as nanowires, micro-platelets, hexagonal micro-disks, and even spherical structures, have been successfully synthesized. The literature "Zheng, Yang, Qian, et al.Large and Ultrastable All-Inorganic CsPbBr₃ Monocrystalline Films:Low-Temperature Growth and Application for High-Performance Photodetectors[J]Advanced Materials,2017,30(44): 1802110-; as for the rod-shaped single crystal, a large-volume single crystal is mostly prepared by the Bridgman method, for example: constantinos et al used equimolar amounts of PbBr₂And CsBr in a sealed fused silica ampoule at 600 ℃ to form orthorhombic CsPbBr₃Single Crystal (C.C.Stoumpos, C.D.Malliakas, J.A.Peters, Z.F.Liu, M.Sebastian, J.Im, T.C.Chasapis, A.C.Wibowo, D.Y.Chung, A.J.Freeman, B.W.Wessels and M.G.Kanatzidis, Crystal Growth of the Perovskite Semiconductor CsPbBr₃A New Material for High-Energy Radiation Detection, Crystal growth Des, 2013,13(7), 2722-2727.). In 2018, Y.Hui et al synthesized CsPbBr3 single crystal by using improved Bridgman method, and the hole electron mu tau product of the CsPbBr3 single crystal is 1.34 multiplied by 10^-3cm² V^-1And 8.77X 10^-4cm² V^-1(Y.H.He,L.Matei,H.J.Jung,K.M.McCall,M.Chen,C.C.Stoumpos,Z.F.Liu,J.A.Peters,D.Y.Chung,B.W.Wessels,M.R.Wasielewski,V.P.Dravid,A.Burger and M.G.Kanatzidis,High spectral resolution of gamma-rays at room temperature by perovskite CsPbBr₃single crystals, nat. commun.,2018,9,1609) however, the Bridgman melt growth method requires raising the temperature to above 500 ℃ and multiple purification processes to purify the raw material greatly increases the manufacturing cost, compared to which the solution synthesis perovskite single crystal method is less costly and more simple and easy to implement. Dnity et al use DMSO/DMF/cyclohexanol (CyOH) mixed solvent to expand the temperature range of solubility drop, and use Inverse Temperature Crystallization (ITC) method to grow larger bulk CsPbBr₃Single crystal (D.N. Dirin, I.Cherniukh, S.Yakunin, Y.Shynkarenko and M.V.Kovalenko, Solution-Grown CsPbBr3 Perovskite Single Crystals for Photon Detection, chem.Mater.,2016,28(23), 8470-. Feng et al synthesized a Low defect density rectangular single crystal (J defect density CsPbBr3 single crystals grown by an additive assisted method for gamma-ray detection [ J defect density ] by adjusting additive CB (acetylcholine)]Journal of Materials Chemistry C,2020,8.), probe made with the crystal from¹³⁷The Cs source gives an energy spectrum with a resolution of 5.5% at 662 keV. The document "Kurahashi N, Nguyen V C, Sasaki F, et al]Applied Physics Letters,2018,113(1):011107, "reports the synthesis of organic perovskite polycrystals in capillaries by potting and studies on their laser emission characteristics, by controlling the diameter of the tube body,the control from multi-mode laser to single-mode laser emission is successfully realized.

In summary, the current research on the linear-rod-shaped perovskite single crystal includes nano/micro wires and rod-shaped crystals, the nano-micro level crystals generally grow on a silicon wafer or a mica wafer substrate, although the one-dimensional crystals have a high specific surface area and can limit carrier transportation in a one-dimensional channel, the actual laser equipment is not easily assembled by processing independent and fragile microcrystals, and the storage service life of the laser equipment is limited due to the sensitivity to external air and moisture; the crystal is synthesized by a template limitation method, only organic and inorganic hybrid perovskite polycrystal can be synthesized in the tube at present, and the length is only hundreds of micrometers. Therefore, from the perspective of devices, the perovskite single crystal fiber with single dispersion, micron-sized diameter and centimeter-sized length is still the key for improving the application of perovskite single crystal in photoelectric devices.

Disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention mainly aims to provide a method for preparing a centimeter-level length perovskite single crystal fiber limited by a template. The preparation method synthesizes centimeter-level continuous single crystals, reduces the contact between perovskite crystals and external environments (water, air and the like) through the protection of the quartz template, reduces the crystal loss, and is suitable for various organic-inorganic hybrid and inorganic perovskite formulas.

The invention also aims to provide the centimeter-length perovskite single crystal fiber prepared by the method.

The invention also aims to provide application of the perovskite single crystal fiber with the centimeter-level length in preparation of a single crystal perovskite optical fiber.

The purpose of the invention is realized by the following technical scheme:

a preparation method of centimeter-level length perovskite single crystal fiber comprises the following steps:

(1) absorbing the perovskite precursor solution into a hollow fiber pore channel by capillary force or injecting an external force into the hollow fiber pore channel;

(2) drying the fiber pore canal obtained in the step (1) in a vacuum drying oven.

Preferably, the drying time is 48-96h, and the drying temperature is 70-85 ℃.

Preferably, the hollow fiber pore canal is a microcapillary; further preferably, the inner diameter of the microcapillary tube is 5 to 50 μm.

Preferably, the perovskite precursor is an iodine-based precursor, a chlorine-based precursor or a mixed halogen precursor.

Preferably, the solvent of the perovskite precursor solution is a dimethyl sulfoxide-N, N-dimethylformamide double solvent or a dimethyl sulfoxide-N, N-dimethylformamide-cyclohexanol triple solvent.

Preferably, the perovskite precursor comprises lead bromide and cesium bromide; the molar ratio of the lead bromide to the cesium bromide is 1: 1-2: 1. further preferably, the molar concentration of the cesium bromide in the solvent is in a range of 0.2-0.5M. More preferably, the purities of the lead bromide and the cesium bromide are both higher than 99.9%.

Preferably, the preparation of the perovskite precursor solution comprises the following steps:

(a) dissolving a perovskite precursor in dimethyl sulfoxide, adding another solvent, and stirring for 5-8h to obtain a precursor suspension solution;

(b) centrifuging the precursor suspension solution obtained in the step (a) for 5-10min under the condition of 8000rpm of 5000-;

(c) and (c) filtering the solution obtained in the step (b) by using a PTFE filter with the aperture of 0.22-0.45 mu m to obtain the perovskite precursor solution.

Further preferably, the other solvent is a mixed solvent of cyclohexanol and dimethylformamide or dimethylformamide; the mol percentage of the dimethyl sulfoxide in the total solvent is 50-80%.

The perovskite single crystal fiber with centimeter-level length prepared by the preparation method.

The perovskite single crystal fiber with the centimeter-level length is applied to preparing the single crystal perovskite optical fiber.

The centrifugal filtration in the steps (b) and (c) can remove excessive undissolved lead bromide and fine impurities in the solution, avoid dust impurities from becoming nucleation sites and reduce the number of crystal nuclei.

Dimethyl sulfoxide (DMSO) is good solvent for lead bromide and cesium bromide, and PbBr is adjusted₂Molar ratio to CsBr 1: 1-2: 1, which is beneficial to obtaining pure CsPbBr₃Phase, adding excess lead bromide (PbBr)₂) The solubility of cesium bromide (CsBr) can be improved.

The boiling point of the solvent can be reduced by adopting the mixed solvent, and the inverse solubility phenomenon of the solute along with the temperature rise can be improved, so that the solubility curve is smoother, and the slow crystal precipitation is facilitated.

In the step (2), the drying temperature is 70-85 ℃, and the cesium lead bromide CsPbBr is adopted₃The crystal phase is changed from a tetragonal phase to an orthorhombic phase at 88 ℃, and the drying temperature is selected to be below the phase transition temperature, so that a single crystal phase is generated conveniently.

The template limiting method for preparing the continuous perovskite single crystal is characterized in that a solution is sucked by utilizing the capillary force of a capillary, a precursor solution is limited in a pore canal with the aperture being micron-sized, the precipitation of the continuous single crystal is controlled by adjusting the concentration, the multi-solvent ratio and the reaction temperature, the synthesized single crystal is attached to the wall of the canal and is cylindrical, the central wavelength of fluorescence emission in an emission spectrum fluctuates between 530nm and 532nm, a light-emitting waveband is green light, an obvious ASE phenomenon appears under the excitation of laser, and the potential of realizing the output of the laser is realized. A novel method for synthesizing single crystal perovskites is provided, which can be used for synthesizing single crystal optical fibers.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the invention, through the combination of an ITL (inversion temperature method) and a template method, centimeter-level perovskite single crystals are prepared in the template, and the prepared single crystals grow in the quartz capillary tube, are tightly attached to the quartz template, have good continuity, and are beneficial to reducing the contact between the prepared single crystals and the outside, thereby reducing the crystal loss. The diameter of the single crystal can be adjusted with the diameter of the template in the range of 5-100 microns.

(2) The method can be used for absorbing or injecting various liquid gain media by depending on capillary force, changing the solubility curve of the solute by adjusting the solvent ratio, is suitable for various precursor formulas, can be expanded to other halogen perovskites, and is simultaneously suitable for preparing organic-inorganic hybrid perovskites and all-inorganic perovskite single crystal fibers.

(3) The in-tube transistor prepared by the method has obvious ASE phenomenon and can realize laser output.

Drawings

FIG. 1 is a laser spectrum, in-line optical microscope morphology and single crystal analysis of the perovskite single crystal fiber prepared in example 1.

FIG. 2 is a laser spectrum, in-line optical microscope morphology and single crystal analysis of the perovskite single crystal fiber prepared in example 2.

FIG. 3 is a laser spectrum, in-line optical microscope morphology and single crystal analysis plot of the perovskite single crystal fiber prepared in example 3.

FIG. 4 is a laser spectrum of the perovskite single crystal fiber prepared in example 4.

FIG. 5 is a laser spectrum of the perovskite single crystal fiber prepared in example 5.

FIG. 6 is an absorption and emission spectrum of the perovskite single crystal fiber prepared in example 4.

FIG. 7 is a cross-sectional SEM of a perovskite single crystal fiber.

Fig. 8a and 8b are external views of perovskite single crystal fibers.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.

Example 1

(1) Weighing cesium bromide CsBr and lead bromide PbBr by using electronic balance₂They were mixed in a ratio of 1: 2, the molar concentration of cesium bromide is 0.5M, magnetically stirring is carried out for 5 hours at room temperature, and then DMF with the same volume is added to obtain 0.25M perovskite precursor solution;

(2) centrifuging the stirred precursor suspension solution for 5min at 8000rpm to remove excessive PbBr₂Powder;

(3) further filtering the precursor solution by using a 0.22 mu mPTE filter to remove fine impurities;

(4) sucking the precursor solution into a micro-capillary with the inner diameter of 0.039mm by capillary force, placing the micro-capillary in a glass culture dish, and marking;

(5) drying the sample in the tube for 72h in a vacuum drying oven, wherein the drying temperature is set to 80 ℃, and then the continuous monocrystal perovskite can be obtained, the laser spectrum of which is shown in figure 1, and the embedded optical microscope and monocrystal analysis graph; the appearance is shown in fig. 8a and 8b, and the length can be measured to be 8 mm.

The embedded microscope picture in fig. 1 shows that the single crystal grows tightly attached to the tube wall, the whole crystal is uniform and smooth, and no bubble inclusion exists, as shown in fig. 7SEM, the capillary is broken off, the section is observed, and it can be seen that the crystal is tightly filled, has no hole, and is cylindrical. FIG. 1 is a single crystal diffraction analysis chart showing that the crystal is diffracted by X-rays, and the diffraction pattern is speckled and distributed on a series of straight lines, indicating that the crystal is a single crystal. And then, carrying out optical characterization on the crystal, completely pumping the crystal in the tube by using a femtosecond laser (TOPAS Prime, 400nm, 1kHz and 120fs) vertical to the tube body, wherein the luminescent intensity is nonlinearly increased and the full width at half maximum of the spectrum is nonlinearly reduced with the increase of the pumping power, so that the crystal presents ASE characteristics.

Example 2

(1) Weighing cesium bromide CsBr and lead bromide PbBr by using electronic balance₂They were mixed in a ratio of 1: 2 in 2.4ml of DMSO (dimethyl sulfoxide), magnetically stirring at room temperature for 8 hours until the solution is fully dissolved, adding 0.6ml of DMF, and continuously stirring for half an hour until the solution is fully dissolved to obtain a 0.5M perovskite precursor solution;

(5) and drying the sample in the tube for 72h in a vacuum drying oven, wherein the drying temperature is set to 80 ℃, and thus the continuous monocrystal perovskite can be obtained. The laser spectrum is shown in figure 2, and the length can be measured to be 7mm by embedding an optical microscope and a single crystal analysis picture.

The microscope picture embedded in fig. 2 shows that the single crystal grows tightly attached to the tube wall, the whole crystal is uniform and smooth, and no bubble crack exists, as shown in fig. 7SEM, the capillary is broken off, and the section is observed, so that the crystal is tightly filled, has no hole, and is cylindrical. FIG. 2 is a single crystal diffraction analysis chart showing that the crystal is diffracted by X-rays, and the diffraction pattern is speckled and distributed on a series of straight lines, indicating that the crystal is a single crystal. And then, carrying out optical characterization on the crystal, completely pumping the crystal in the tube by using a femtosecond laser (TOPAS Prime, 400nm, 1kHz and 120fs) vertical to the tube body, wherein the luminescent intensity is nonlinearly increased and the full width at half maximum of the spectrum is nonlinearly reduced with the increase of the pumping power, so that the crystal presents ASE characteristics.

Example 3

(1) Weighing cesium bromide CsBr and lead bromide PbBr by using electronic balance₂They were mixed in a ratio of 1: 2, the molar concentration of cesium bromide is 0.5M, the mixture is magnetically stirred for 8 hours at room temperature, a mixed solvent of cyclohexanol (CyOH) and Dimethylformamide (DMF) with the same volume is dripped, the mixture is stirred for half an hour, and the ratio of the mixed solvent is 5.1g to 9.1g, so that a perovskite precursor solution with the concentration of 0.25M is formed;

(2) centrifuging the stirred precursor suspension solution for 6min at 8000rpm to remove excessive PbBr₂Powder;

(5) and (3) drying the sample in the tube for 72h in a vacuum drying oven, setting the drying temperature to 80 ℃, and obtaining the continuous monocrystal perovskite, wherein the laser spectrum of the continuous monocrystal perovskite is shown in figure 3, the embedded optical microscope and monocrystal analysis graph are shown, and the length of the product is 4 mm.

The microscope picture embedded in fig. 3 shows that the single crystal grows tightly attached to the tube wall, the whole crystal is uniform and smooth, and no bubble crack exists, as shown in fig. 7SEM, the capillary is broken off, the section is observed, and it can be seen that the crystal is tightly filled, has no hole, and is cylindrical. FIG. 3 is a single crystal diffraction analysis chart showing that the crystal is diffracted by X-rays, and the diffraction pattern is speckled and distributed on a series of straight lines, indicating that the crystal is a single crystal. And then, carrying out optical characterization on the crystal, completely pumping the crystal in the tube by using a femtosecond laser (TOPAS Prime, 400nm, 1kHz and 120fs) vertical to the tube body, wherein the luminescent intensity is nonlinearly increased and the full width at half maximum of the spectrum is nonlinearly reduced with the increase of the pumping power, so that the crystal presents ASE characteristics. The length of the product is 4 mm.

Example 4

(1) Weighing cesium bromide CsBr and lead bromide PbBr by using electronic balance₂They were mixed in a ratio of 1: 2, the molar concentration of cesium bromide is 0.5M, the mixture is magnetically stirred for 8 hours at room temperature, a mixed solvent of cyclohexanol (CyOH) and Dimethylformamide (DMF) with the same volume is dripped, the mixture is stirred for half an hour, the ratio of the mixed solvent is 7.1g to 7.1g, the mixing temperature is 30 ℃, and a 0.25M perovskite precursor solution is formed;

(3) further filtering the precursor solution by using a 0.22 mu m PTFE filter to remove fine impurities;

(5) and (3) drying the sample in the tube for 72h in a vacuum drying oven, wherein the drying temperature is set to 80 ℃, so that the continuous monocrystal perovskite can be obtained, the optical microscope and the laser spectrum of the continuous monocrystal perovskite are shown in figure 4, and the length of the product is 5 mm.

The microscope picture embedded in fig. 4 shows that the single crystal grows tightly attached to the tube wall, the whole crystal is uniform and smooth, and no bubble crack exists, as shown in fig. 7SEM, the capillary is broken off, and the section is observed, so that the crystal is tightly filled, has no hole, and is cylindrical. FIG. 4 is a single crystal diffraction analysis chart showing that the crystal is diffracted by X-rays, and the diffraction pattern is speckled and distributed on a series of straight lines, indicating that the crystal is a single crystal. And then, carrying out optical characterization on the crystal, completely pumping the crystal in the tube by using a femtosecond laser (TOPAS Prime, 400nm, 1kHz and 120fs) vertical to the tube body, wherein the luminescent intensity is nonlinearly increased and the full width at half maximum of the spectrum is nonlinearly reduced with the increase of the pumping power, so that the crystal presents ASE characteristics.

FIG. 6 is an absorption and emission spectrum of the synthesized crystal of example 4. The fluorescence peak has a center wavelength of about 530nm and a full width at half maximum FWHM of about 26 nm. According to its absorption spectrum, CsPbBr₃Has good absorption performance for ultraviolet-visible light (partial visible light) and no other corresponding exciton absorption peak, which is mainly determined by the energy band structure of the crystal. The perovskite is a direct gap semiconductor, and the absorption spectrum is further plotted according to the Tauc Plot method, namely an insertion graph, and the Eg is obtained to be 2.40 ev. The band gap value of the crystal grown by the above preparation method is consistent with the band gap value of a single crystal grown by the antisolvent vapor assisted crystallization method at room temperature and a single crystal grown by the ITC method.

Example 5

(1) Weighing cesium bromide CsBr and lead bromide PbBr by using electronic balance₂They were mixed in a ratio of 1: 2 is dissolved in 1.8ml of dimethyl sulfoxide DMSO, magnetically stirred for 8 hours at room temperature, and then 1.2ml of DMF is added dropwise and stirred for half an hour to be fully dissolved. Forming 0.5M perovskite precursor solution;

(5) and (3) drying the sample in the tube for 72h in a vacuum drying oven, wherein the drying temperature is set to 80 ℃, so that the continuous monocrystal perovskite can be obtained, the optical microscope and the laser spectrum of the continuous monocrystal perovskite are shown in figure 5, and the length of the product is 5 mm.

The microscope picture embedded in fig. 5 shows that the single crystal grows tightly attached to the tube wall, the whole crystal is uniform and smooth, and no bubble crack exists, as shown in fig. 7SEM, the capillary is broken off, and the section is observed, so that the crystal is tightly filled, has no hole, and is cylindrical. FIG. 5 is a single crystal diffraction analysis chart showing that the crystal is diffracted by X-rays, and the diffraction pattern is speckled and distributed on a series of straight lines, indicating that the crystal is a single crystal. And then, carrying out optical characterization on the crystal, completely pumping the crystal in the tube by using a femtosecond laser (TOPAS Prime, 400nm, 1kHz and 120fs) vertical to the tube body, wherein the luminescent intensity is nonlinearly increased and the full width at half maximum of the spectrum is nonlinearly reduced with the increase of the pumping power, so that the crystal presents ASE characteristics.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. The preparation method of the centimeter-level length perovskite single crystal fiber is characterized by comprising the following steps:

2. The method according to claim 1, wherein the drying time is 48 to 96 hours and the drying temperature is 70 to 85 ℃.

3. The method of claim 1, wherein the hollow fiber pore is a microcapillary; the inner diameter of the microcapillary tube is 5-50 μm.

4. The production method according to claim 1, wherein the perovskite precursor is an iodine-based precursor, a chlorine-based precursor, a mixed halogen precursor; the solvent of the perovskite precursor solution is dimethyl sulfoxide-N, N-dimethyl formamide double solvent or dimethyl sulfoxide-N, N-dimethyl formamide-cyclohexanol triple solvent.

5. The production method according to claim 1, wherein the perovskite precursor includes lead bromide and cesium bromide; the molar ratio of the lead bromide to the cesium bromide is 1: 1-2: 1.

6. The method according to claim 5, wherein the molar concentration of cesium bromide in the solvent is in the range of 0.2 to 0.5M.

7. The production method according to claim 1, characterized in that the production of the perovskite precursor solution comprises the steps of:

(c) filtering the solution obtained in the step (b) by using PTFE with the aperture of 0.22-0.45 mu m to obtain the perovskite precursor solution.

8. The production method according to claim 7, wherein the other solvent is a mixed solvent of cyclohexanol and N, N-dimethylformamide or N, N-dimethylformamide; the mol percentage of the dimethyl sulfoxide in the total solvent is 50-80%.

9. Centimeter-length perovskite single-crystal fibers prepared by the preparation method according to any one of claims 1 to 8.

10. Use of a centimeter-length perovskite single crystal fiber according to claim 9 for the preparation of a single crystal perovskite optical fiber.